Description:Sin City committed one of Hollywood's deadliest this weekend: boring moviegoers.The result was one of the higher-profile Hollywood flops of the summer. Sin City: A Dame to Kill For, the sequel to the 2005 fanboy favorite, mustered just $6.5 million and eighth place, according to studio estimates from Rentrak.The opening fell well below expectations, with analysts having anticipated a No. 1 debut of at least $15 million.(0:46)